Typical conventional chemical dispensing systems use dry chemical tablets. These dry tablets are generally placed in the toilet tank and are composed so that the dry tablets slowly dissolve in the tank water, releasing a cleaning or disinfectant agent. The cleaning agent is then released into the toilet bowl when the toilet is flushed.
In a later refinement, a housing was added to the dispenser. This semi-enclosed housing held the dry chemical tablet and was attached on the side of inner surface of the toilet tank, placing the dry tablet in the tank water. This housing served to slow down the release of the chemical.
More recently, devices with a pressurized secondary tank were developed to replace the reservoir of water in the water tank that is used to flush the toilet. These devices are installed within the water tank and may contain chemical cleaners or disinfectants. These devices use the pressurized secondary tank to dispense water and chemicals into the toilet bowl to flush and clean the toilet bowl.
These types of conventional systems have several disadvantages. For example, in the dry tablet systems, as the dry chemical dissolves, the surface area of the tablet is reduced. Further, the rate at which the chemical dissolves into the tank water is related to the surface area of the tablet. Therefore, as the tablet size is reduced, for a given time period the concentration of the chemical in the tank water diminishes. Further, the time between flushes is also related to the concentration of the chemical in the treated tank water. For example, if the toilet is unused for several days, the chemical concentration of the tank water tends to significantly increase. It is possible that an entire tablet can be dissolved and be used in a single flush. Thus, the amount of chemical dispensed into the toilet bowl is not consistent, which tends to both decrease the effectiveness of the cleaning/disinfecting process and waste the chemical.
Moreover, because the chemical is dissolved into the tank water (which is mainly used to flush the toilet), most of the chemical is wasted in that the chemical is merely flushed away rather than being retained in the toilet bowl where the chemical can effectively clean and/or disinfect the toilet bowl. This deficiency also applies to the pressurized secondary tank systems with added(s). More specifically, the flushing process uses roughly two thirds of the treated solution to flush the contents of the toilet bowl into the sewage system. Thus, only a residual amount of the chemically treated water is left to serve as the standing water in the toilet bowl. In addition, the pressurized secondary tank systems tend to be complex and costly.
Accordingly, there is a need for a simple, low cost, efficient dispensing system for a toilet that provides a predetermined amount of chemical into the toilet bowl without wasting chemical in the flushing process.